4种粗糙度铝板的2.52 THz后向散射测量

Measurement of 2.52THz Back Scatteringin Aluminium Plates with Four Kinds of Roughness

太赫兹目标散射特性是表征目标对太赫兹波散射能力的一个重要指标。搭建了束宽约100mm的带有屏蔽舱的2.52THz目标散射测量系统。利用该系统分别对粗糙度Ra为1.6,3.2,6.3,12.5μm,宽为40mm和45mm的铝方板进行了后向散射的测量实验。通过对数据的分析以及与理论公式的对比,验证了此系统的可行性。实验结果表明,相同尺寸不同粗糙度铝板后向散射最大值变化很小,随着粗糙度增大,后向散射从高点下降,斜率有增大趋势。

Terahertz target scattering characteristic is a very important index to represent the target′s scattering ability of Terahertz. A system to measure target′s scattering characteristic of 2.52 THz is established. The system has a shield compartment, and the beam′s waist width is about 100 mm. With this system, a back scattering measurement experiment is conducted on square plates whose roughness Ra are respectively 1.6, 3.2, 6.3, 12.5 μm. The square plates are 40 mm and 45 mm wide. Through analyzing the experimental data and comparing them with the theoretical formula, the feasibility of this system is verified. The experimental results show that the back scattering′s maximum value of the aluminum plates with different roughnesses changes little, when the size of the aluminum plates is the same. While the roughness increases, the back scattering declines from the peak and the gradient trends greater.